The invention relates to an arrangement for determining the image sharpness of originals in a long strip of originals to be passed through a copying or photoprinting machine.
In the development of film exposed by amateur photographers, it has become more and more the practice to connect the individual film strips end-to-end, by gluing or the like, in order to form a very long web of film material which can be transported through a fast-operating automatic copying or printing machine. Some machines of this type produce a copy or print of each original passing through the machine. Others are selective and produce a copy or print of only those originals having an average density lying within a predetermined range of densities. Originals whose average density is outside such range are not copied.
However, it is well known that in the course of processing a large number of such originals, many originals will be encountered which, although they do have an average density within the preselected range, are nevertheless of so poor a quality, due to extreme lack of image sharpness, that they are not worth printing. Copies of originals which are unclear due to improper focal settings and/or camera movements during picture taking are of course in general not desired by the photographer, and the paying of money for such unsatisfactory prints will of course be rather irritating to the consumer.